My best bet would be to call your Local mercedes parts center, give them your VIN and they should be able to decode whether you have ESP or not.

There could be many reason why the brakes could lock up...Maybe due to failed master cylinder, old, contaminated brake fluid, failed calipers, abs module etc...

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2001 E55

2001 E320 Sedan

2001 Subaru Legacy

2006 SLK280

2016 Subaru Outback 3.6